A film passes through many programs: modelling, animation, effects, lighting, compositing. Each step must read what the step before wrote, without losing anything. The big studios solved this with their own file formats and then gave them away as open source. Today most of them are kept by the Academy Software Foundation (ASWF), part of the Linux Foundation. Animux installs them with their tools.
Pixar · open source since 2016
OpenUSD
Universal Scene Description · .usd .usda .usdc · viewer: usdview
The problem: on one shot, modelling, layout, animation and lighting all want to work at the same time.
The answer: a scene made of layers. Each department writes its own layer on top of the others, and a stronger layer wins. Nobody overwrites anybody's file.
Pixar built USD for its own films and released it in 2016. It is now read by Blender, Houdini, Maya, Unreal and NVIDIA Omniverse.
Source: Pixar, "Open Source Announcement", openusd.org
Sony Pictures Imageworks and ILM · 2010
Alembic
Baked animation cache · .abc · tools: abcls, abctree
The problem: a rig only works in the program it was built in.
The answer: the finished movement is baked: every vertex position on every frame is stored. The cache plays the same in Blender, Gaffer, Houdini or Maya, with no rig needed.
Imageworks and Industrial Light & Magic announced it together at SIGGRAPH 2010.
Source: Alembic project, alembic.io
Industrial Light & Magic · open source since 2003
OpenEXR
High dynamic range images · .exr · viewer: DJV
The problem: a PNG cuts off light: the sun and a lamp both become plain white.
The answer: EXR keeps the real brightness of every pixel, so exposure can be changed later, and stores passes (light, shadow, reflections, depth) as separate layers in one file for compositing.
Source: OpenEXR project, openexr.com
Sony Pictures Imageworks
OpenColorIO
Colour management · config.ocio · ACES
The problem: the same frame looks different in the 3D program, the compositor and the editor.
The answer: one colour configuration shared by every program, so a red stays the same red from render to final grade. Blender, Krita, Gaffer and DaVinci Resolve all use it.
Source: OpenColorIO project, opencolorio.org
DreamWorks Animation · 2012
OpenVDB
Volumes · .vdb · smoke, fire, clouds
The problem: smoke and clouds are mostly empty air, and storing every point of a box wastes memory.
The answer: a sparse grid that stores only the cells where something is. Blender writes its smoke simulations as VDB, and renderers read them.
Source: OpenVDB project, openvdb.org
Commands and examples for each format: Pipeline formats.